Required if applicable. Pre-AACR2 only/Required if applicable. Pre-AACR2 only

ǂc

Location of an event (NR)

Required if applicable/Required if applicable

ǂd

Active dates (NR)

Required if applicable/Required if applicable

ǂe

Relator term (R)

Required if applicable/Required if applicable

ǂg

Miscellaneous information (R)

Required if applicable/Required if applicable

ǂv

Form subdivision (R)

Required if applicable/Required if applicable

ǂx

General subdivision (R)

Required if applicable/Required if applicable

ǂy

Chronological subdivision (R)

Required if applicable/Required if applicable

ǂz

Geographical subdivision (R)

Required if applicable/Required if applicable

ǂ0

Authority record control number or standard number (R)

Optional/Optional

ǂ2

Source of heading or term (NR)

Required if applicable/Required if applicable

ǂ3

Materials specified (NR)

Optional/Optional

ǂ4

Relator code (R)

Optional/Optional

ǂ8

Field link and sequence number (R)

Optional/Optional

Definition

A topical subject used as a subject added entry. Subject added entries are assigned to a bibliographic record to provide access according to established subject cataloging principles and guidelines. Any institution assigning subject headings based on the lists and authority files identified in the 2nd indicator position or in subfield ǂ2 may use field 650. A topical subject added entry consists of a general subject term including the name of an event or object. Use for the following types of topical subject added entries:

General terms (e.g., Dogs or Chemistry) of the type listed in Library of Congress Subject Headings and other thesauri

Names or terms applied to individual objects or classes of objects (e.g., Universities and colleges)

Systematic names of families, genera, species in botany and zoology and chemical compounds (e.g., Hemiptera)

Use field 650 also for a geographic name (e.g., Iran in the Koran), the name of a corporate body (e.g., Catholic Church and humanism) or a title (e.g., Bible and atheism) included in a phrase subject heading.

Use field 690 (Local Subject Added Entry–Topical Term) if the topical subject entry is locally devised (i.e., not based on LC, AC, NLM, NAL, NLC or Sears).

1st Indicator

Level of subject. The level of the subject entry. Use the 1st indicator to distinguish primary and secondary descriptors.

No information provided. No information as to the level of the subject term is provided.

650

0

Architecture, Modern ǂy19th century.

0

No level specified. The level of the subject term could be determined, but is not specified.

650

0

0

Flour and feed trade ǂv Periodicals.

1

Primary. A subject covers the main focus or subject content of the material.

650

1

2

Cardiovascular Physiology ǂv Congresses.

650

1

7

Career Exploration. ǂ2 ericd

650

1

7

Cooks. ǂ2 ericd

2

Secondary. A subject covers a less important aspect of the content of the material.

650

2

2

Carbon Monoxide ǂx metabolism ǂv Congresses.

650

2

7

Food Service. ǂ2 ericd

650

2

7

Junior High Schools. ǂ2 ericd

650

2

7

Simulation. ǂ2 ericd

[Primary and secondary subject content is identified.]

2nd Indicator

Thesaurus. The thesaurus or subject heading system used in constructing the subject heading.

0

Library of Congress subject heading. The formulation of the subject added entry conforms to Library of Congress Subject Headings (LCSH). This includes:

Topical headings (or topical headings and subdivisions) found in the LC subject authority file or in the latest edition of LCSH, including the latest supplements

Topical headings found in the LC subject authority file or in the latest edition of LCSH to which is added a free-floating or regular subdivision according to the rules stated in the Subject Headings Manual (formerly called Subject Cataloging Manual: Subject Headings), particularly subdivisions listed in the pattern lists and geographic subdivisions

Topical headings not printed in LCSH in the past, but which have been used by LC and which are not likely to have changed (e.g., names of chemical compounds)

Certain music headings with qualifiers specifying instruments or vocal parts when the main heading has a general scope note printed in LCSH, with or without a general see also reference

Use of value 0 requires that the added entry is appropriate for use in LCSH.

1

LC subject heading for children's literature. The formulation of the subject added entry conforms to the "AC Subject Headings" section of Library of Congress Subject Headings. Use of value 1 requires that the added entry is appropriate for use in the LC Annotated Card Program.

2

Medical subject heading. The formulation of the subject added entry conforms to the National Library of Medicine (NLM) authority files. Use of value 2 requires that the added entry is appropriate for use in the NLM authority files.

3

National Agricultural Library subject authority file. The formulation of the subject added entry conforms to the National Agricultural Library (NAL) subject authority file. Use of value 3 requires that the added entry is appropriate for use in the NAL authority files.

4

Source not specified. The formulation of the subject added entry conforms to a controlled list, but the source cannot be specified by one of the thesaurus or subject heading systems covered by the other 2nd indicator values or by a code for a specific subject heading list in subfield ǂ2. Use field 653 (Index Term–Uncontrolled) to record terms that are not derived from controlled subject heading lists.

5

Canadian subject heading. The formulation of the subject added entry conforms to the Canadian Subject Headings. Use of value 5 requires that the added entry is appropriate for use in Canadian Subject Headings.

6

Répertoire de vedettes-matière. The formulation of the subject added entry conforms to the Répertoire de vedettes-matière maintained by the Bibliothèque de l'Université de Laval. Use of value 6 requires that the added entry is appropriate for use in Répertoire de vedettes-matière.

7

Source is specified in subfield ǂ2 . Subject headings or terms based on other subject authorities (i.e., on authorities other than those listed here). Identify the source in subfield ǂ2.

650

7

Children of pregnant women. ǂ2 henn

8

Sears subject heading. OCLC-defined value. The formulation of the subject added entry conforms to the Sears List of Subject Headings.

Subfields

ǂa Topical term or geographic name as entry element

A topical subject or geographic name used as an entry element for a topical term. Enter parenthetical qualifying information associated with the term also in subfield ǂa.

650

7

"Mad scientist" (Concept) ǂ2 henn

ǂb Topical term following geographic name as entry element

A topical term that is entered under a geographic name in subfield ǂa. Pre-AACR2 headings only.

650

0

Caracas. ǂb Bolivar Statue.

[Pre-AACR2.]

ǂc Location of an event

The location at which an event occurred.

ǂd Active dates

The time during which an event occurred.

ǂe Relator term

A term that specifies the relationship between the topical heading and the described materials, e.g., subject.

650

0

Unicorns, ǂe depicted.

[Bayeux Tapestry, showing a unicorn]

ǂg Miscellaneous information

Data element that is not more appropriately contained in another defined subfield.

ǂv Form subdivision

A specific kind or genre of material defined by the thesaurus being used. Use only when a form subject subdivision is added to a main term. Use subfield ǂv also for form terms when they function as indicated above. Use subfield ǂx if the terms function as general subdivisions. A form subdivision in subfield ǂv is generally the last subfield in the field. Repeat subfield ǂv if you use more than one form subdivision.

650

0

Dentistry ǂv Juvenile films.

650

7

Women tea-trade executives ǂz London, England ǂv Fiction. ǂ2 henn

ǂx General subdivision

A subject subdivision that is not more appropriately contained in subfield ǂv, ǂy or ǂz. Use subfield ǂx only when a general topical subdivision is added to a main term.

650

0

Racetracks (Horse racing) ǂz United States ǂx History.

ǂy Chronological subdivision

A subject subdivision that represents a period of time. Use only when a chronological subject subdivision is added to a main term.

650

0

Architecture, Modern ǂy 19th century.

ǂz Geographical subdivision

A geographic subject subdivision. Use only when a geographic subject subdivision is added to a main term.